Threaded connections are quite reliable and effective. They are considered one of the most common and cost-effective. However, when exposed to vibration, there is a possibility of their weakening. This can often be seen in the example of nuts, randomly untwisted during operation of various devices. Therefore, methods have been developed that can reduce this effect or completely eliminate it.
Ways to Avoid Loosening the Nut
1. Use the washer. This method is one of the most common. It is used in the manufacture of household appliances and some types of industrial equipment. It does not have a high degree of reliability and provides protection against arbitrary unwinding. A soft metal washer is put on the thread, and then a nut is tightened, squeezing it.
2. Washer and Grover. A more reliable method, practiced, rather than the transport industry. Protects the threaded connection from arbitrary loosening even in the presence of slight vibration. First, a regular washer is put on the thread, and then a grover. Then tighten the nut. Grover here serves as a kind of spring, creating a tension that prevents unwinding.
3. Special nut with lock. The method using a special nut cannot be called the most effective. However, it takes place in world practice, and is used in some types of production.
4. Using a thread lock. The composition is applied to the place where the nut will be located, after which it is put on the thread. This is a fairly effective way to prevent arbitrary loosening, but its effectiveness is affected by temperature changes, high humidity and exposure to active substances. Therefore, its scope is limited.
5. The use of two or more nuts. One of the most reliable methods. Two nuts are screwed onto the thread at once. After clamping the first, a separate tightening of the second is carried out, holding the first in its original position and even trying to unscrew it a little.
6. Fixing with a cotter pin. This is the most reliable method that can withstand almost any external impact and strong vibration. It is used in critical areas. The nut is fully tightened. Then, using a drill and a thin drill, make a hole piercing it with the bolt. A hairpin is inserted into the resulting hole, the antennae of which are unbent, preventing loss. Such a nut can only be loosened with a very strong rotational action in the direction of the thread.